


Amazing Grace

by frozenCinders



Category: Fate/stay night & Related Fandoms
Genre: M/M, PWP
Language: English
Status: Completed
Published: 2017-10-04
Updated: 2017-10-04
Packaged: 2019-01-09 01:51:40
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,848
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12266460
Author URL: https://archiveofourown.org/users/frozenCinders/pseuds/frozenCinders
Summary: "Is your little hymn about me?" Gilgamesh asked without waiting for his voice to even out."It could be, couldn't it?"Gilgamesh scoffed, finally getting up to walk over to Kirei."I'll be forever yours, you say?""And I, yours," Kirei affirmed, unflinching.





	Amazing Grace

**Author's Note:**

> the idea behind this one was "kirei singing is so cute, so wholesome. i need less rated e fics on my front page anyway" and then gil started running his damn mouth
> 
> why does everything i touch turn to smut

Kirei was singing a hymn. There was no choir to join him as nobody was even at the church but him. Except for Gilgamesh, of course: the lone audience to Kirei's performance. And he laughed.

It wasn't as if the lyrics were funny- not objectively. But the fact that it was Kirei singing these innocent lyrics was what made it amusing. Kirei didn't react at all to Gilgamesh's laughter, continuing his singing of Amazing Grace as if he were truly alone.

When Kirei would read the bible aloud, Gilgamesh of course found it somewhat amusing since Kirei didn't actually believe a word of that book. A hypocrite of the highest degree, he crushed people under the weight of their own perceived sins while he himself must be guilty of every sin in that book he cradles so fondly. Was killing people and enjoying their suffering a sin listed in the bible? Gilgamesh laughed again.

"Is it the song that amuses you, Gilgamesh?" Kirei asked, having finished a moment prior. "Or is it my singing?"

"The mere fact that it's you, Kirei," he answered.

Neither of them moved from their places; Gilgamesh remained seated in the pew, lounging comfortably, while Kirei stood facing the altar with his hands behind his back.

"Do you enjoy singing, Gilgamesh?"

"If I did, surely you would have heard me by now. That being said, don't mistake my disinterest for a lack of talent."

"Is that so..?"

Was Kirei challenging him? Was he offended by Gilgamesh's laughter, assuming he thought Kirei was a bad singer? The ridiculousness of the situation made him crack up again.

"Is your little hymn about me?" Gilgamesh asked without waiting for his voice to even out.

"It could be, couldn't it?"

Gilgamesh scoffed, finally getting up to walk over to Kirei.

"I'll be forever yours, you say?"

"And I, yours," Kirei affirmed, unflinching.

"Hm. You are a priest, aren't you? If you desired to be my bride, you could officiate our marriage, could you not?"

"Bride?"

"Yes. Don't tell me you thought you would be the groom and I the bride?"

"We would both be-"

""I pronounce you man and man?' No, you would be my wife."

"And would you carry me like a bride to your bed? Or would it be the opposite?"

Gilgamesh was still standing behind Kirei, but he could tell he was sporting a smug little smile. So he stretched his arms above his head, as if tired, and then swept Kirei right off his feet, scooping him up into his arms. If he'd been smiling after all, it was gone now.

"Look at you. A face befitting a veil," Gilgamesh teased, convinced he was winning the staring contest Kirei initiated.

"Would you further swap our roles, then?" Kirei asked, folding his hands in his lap rather than struggle against Gilgamesh.

"Hmm... I've been meaning to do so at some point. Yes, on our wedding night, I would take your technical virginity."

"Would you, now..?"

"Are you insinuating that you would deny me?"

"No, just that there's a reason it hasn't happened yet. You have practice soaking your tongue in honey, but you're ironically bad at resisting temptation yourself."

"I am not bad at anything."

"Certainly. You're just monumentally good at begging to be fucked when I've barely even looked at you."

Gilgamesh nearly doubled over with laughter, his grip on Kirei tightening so he wouldn't drop him.

"Are we doing this here? Now? Because you should know you can't beat me at this game," Gilgamesh warned, choosing not to specifically remind Kirei that the day was still young and anyone could walk into the church to see and hear them.

"How can I possibly entertain you if I refuse to play your games?" he said, tilting his head to rest it against Gilgamesh's shoulder.

Gilgamesh carried him to the pews only to set him down on his feet. Gilgamesh sat in front of Kirei and beckoned him with a pat on his leg. Kirei huffed through a smile and climbed onto Gilgamesh's lap, placing his knees on either side of him.

"How can I resist being on the receiving end? Your cock is so thick and your mouth so warm as it travels across my body."

"We're getting right into it, then?"

"You belong inside of me, Kirei."

"Just as the keening whimpers I force out of you belong in your voice," Kirei retorted, but Gilgamesh's smile only widened.

"The bedsprings cry out as you fuck me into the mattress, but they're barely audible over me, over what you do to me..."

Gilgamesh was speaking lowly into Kirei's ear now, and Kirei had half a mind to relocate to the mentioned bed rather than inevitably end up fucking in the main hall again. But only half.

"I'm seeing so many stars, I can barely figure out how to beg you to fuck me harder and your pace picks up without me needing to tell you. I don't bother being careful; my nails scrape your back and the pain only urges you on because you know it's a result of you forcing me to lose control."

"Your voice is broken and your body trembling and slick with sweat, yet you cling to me desperately. You tilt your head back, exposing your throat to me, and I-" Gilgamesh did tilt his head back, and Kirei leaned in, "mark you as my own."

He bit down none too gently. Gilgamesh grit his teeth and sucked in a breath as he felt blood trickle down his neck, eager to stain his shirt.

"You made this mess, you'd better clean it up," Gilgamesh warned. Kirei chuckled and lapped the blood up like the vampires he was so accustomed to killing.

"Have I paused the mood? Allow me to resume it," Kirei said, unbuttoning Gilgamesh's shirt and sliding his hands down his torso once his shirt was open.

"You'd love to see me ruined with my own blood, wouldn't you? Wounded and faint and in no state to be played with, yet you only fuck me harder as my eyes beg you to stop."

Kirei let out something between a sigh and a chuckle.

"Why light a path you won't let me follow?"

"It can be fun to pretend, Kirei. So pretend. Imagine."

"You're choking on your own blood-"

"Do you force yourself into my mouth?"

"So quickly that I nearly stumble."

"Mm, if I could still breathe before, I certainly can't now."

Kirei sighed, though his smile didn't falter.

"The sad part about this fantasy is that it assumes you suddenly forgot how to fight. It would be impossible to get that far without being skewered by a thousand weapons."

"Of course," Gilgamesh agreed. "We're pretending, not predicting the future."

Though, with the use of Command Seals, it wasn't entirely impossible. Gilgamesh let that thought leave him easily as Kirei leaned in to lightly brush their lips together. A hand found its way into Gilgamesh's pants and he smiled, turning Kirei's head by pulling his hair to reach his ear.

"That's right, please your king," he purred, giving Kirei's earlobe a nip. "I want to see you on your knees."

Kirei obeyed, pushing away from Gilgamesh to kneel on the floor in front of him. He pulled Gilgamesh's cock out of its confines and wasted no time in letting it hit the back of his throat. Gilgamesh buried his hands in Kirei's hair and held him there, curious to see how long he'd wait to resist.

Kirei's hands remained calmly set on Gilgamesh's thighs, though they began to grip him when Kirei's eyes closed, apparently hitting his limit. So Gilgamesh pulled him off, watching his eyes flutter open and his mouth remain agape. He reacquainted himself with oxygen before leaning back in to continue and Gilgamesh smiled down at him, petting his hair.

This time, he wasn't quite as eager to take the entire length, instead suckling at the tip and slowly inching down the cock the way he knew Gilgamesh liked. Gilgamesh tilted his head back with a soft moan, resting it uncomfortably on the pew. He waited for Kirei to fully engulf him again before raising his head and speaking up.

"I wanna fuck you in bed," he said, slowly coaxing Kirei off his cock.

"Oh? Is today to be the day, then?" Kirei smiled up at him, amused and probably convinced he can turn the tables and end up on top after all.

"We shall consummate our marriage," Gilgamesh said, standing and tucking himself away for the moment.

When they got to Gilgamesh's room, Kirei attempted to corner him onto the bed. Gilgamesh pulled him forward by the arm and pinned him down, though only half of his body was on the bed.

"You don't think I'm serious, Kirei?" he asked, grabbing the lubricant on his nightstand while it was within reach.

"It couldn't be. The King of Heroes is going to do all the work?"

Gilgamesh laughed at that.

"Or what, the priest of this holy church will ride me? I'd love to see your legs trembling afterwards."

"And yet..?"

"And yet I desire to pin you down and have my way with you. Get further up onto the bed."

Gilgamesh started undressing him even as he moved back, and Kirei slipped Gilgamesh's jacket and shirt off his shoulders in return. Gilgamesh quickly shrugged them off and returned to removing Kirei's clothes. In the position they were in, Gilgamesh's first instinct was to climb onto Kirei's lap and expect his arms to wrap around him. But instead, he pulled Kirei's legs apart and kneeled between them before lubing up his fingers.

Kirei didn't say a word as the first finger entered him. He was tense, of course, and unbearably tight. Gilgamesh smiled.

"You're so tough on the outside, but your insides are so soft," he teased, hooking his finger and sending a quick jolt up Kirei's spine.

He was familiar with that spot, but only inside of Gilgamesh's body. He had absolutely no experience with his own. When Gilgamesh pressed against it again, Kirei couldn't help the curt, low moan that escaped him.

"Doesn't it excite you, knowing there's so much more to come? You won't have to do anything, you'll be too overwhelmed anyway."

He began to press in a second finger and noted the way Kirei's legs shook a bit as he opened them just a little further, maybe not even conscious of it. His head was turned, resting on the pillow with his eyes closed and a deep blush on his face for once. It was a beautiful sight.

Once the third finger was inside of him, Gilgamesh hooked them again and mercilessly pressed against Kirei's prostate. He watched as Kirei's hands gripped the sheets, already sweating, his back arching, legs not knowing whether to open further or close around Gilgamesh, and another little moan escaped him.

Gilgamesh pushed harder and brought his other hand up to stroke Kirei and the noises that escaped him were _divine_.

"A-ah," he moaned uncharacteristically, his legs eagerly opening for more.

"I had no idea you had such a side to you," Gilgamesh commented in genuine surprise. Kirei cracked an eye open to look at him.

"I imagine you want a show, don't you..?" The smugness in his voice was entirely silenced by how affected he was.

"And you are absolutely delivering. But don't try to tell me it's an act when that shade of humiliation on your face is so real."

Kirei turned his head so he was facing forward and Gilgamesh watched his throat move as he swallowed. Seeing him so affected and submissive was even more arousing than Gilgamesh had expected.

He pulled his fingers out and moved closer, holding Kirei's thighs as he slowly pushed into him. He heard Kirei suck in a breath and hold it for a moment, and his voice was mixed in when it came out. Gilgamesh sighed contentedly.

"See? You do make a good bride," he said.

Gilgamesh leaned in to kiss Kirei, despite the fact that his lower lip was busy being held by his teeth. Kirei swallowed again and opened his mouth slightly, and Gilgamesh kissed him. He began moving while their mouths were still conjoined, and Kirei broke the kiss just slightly with a gasp before gritting his teeth.

Gilgamesh tapped one of Kirei's hands.

"Grab onto me, not the bed," he ordered. Kirei slowly, hesitantly released the sheets to bring his hands up to Gilgamesh's shoulders.

Kirei was already so affected, his face still bright red and his breathing impossible to regulate. His grip on Gilgamesh's shoulders tightened and loosened in intervals as he slowly rocked into him. Once he found the angle that made Kirei moan softly into his ear, Gilgamesh picked up the pace.

Kirei's hands moved from Gilgamesh's shoulders to his back and Gilgamesh let go of his legs to allow them to wrap around him. He planted his hands onto the bed and smirked down at Kirei, whose short nails were digging into his back.

"Look at what I'm doing to you," Gilgamesh echoed something similar that he'd said earlier. "Look at me, Kirei."

Kirei opened his eyes and let them wander. It must've been strange, seeing their positions switched.

"This is how a bride and a groom make love, isn't it? Face to face?" Gilgamesh asked. "Though, you insisted you're not my bride..."

Kirei seemed like he wanted to respond but couldn't. Gilgamesh didn't relent, and in fact sped up further, watching Kirei throw his head back and stifle a groan.

"Are you resigned now? You're mine. You've always belonged to me, Kirei. You can have this whenever you want."

"Again?" Kirei asked, his voice managing to crack on just one word.

"Oh? We haven't even finished this round yet."

Kirei shook his head, trying to elaborate but the words died in his mouth. Gilgamesh adored the scene before him. He lowered himself to kiss down Kirei's jaw to his neck. An unusually high whimper caught in his throat.

"Don't hold your noises back, Kirei. I want your voice to bounce off the walls and deafen me."

Gilgamesh kissed him again to open his mouth and Kirei finally moaned openly. His eyes were shut again and the heat from his face could melt snow. Gilgamesh slowed his pace.

"Is this how you imagined it would feel? While you drove your cock into me, did you think I would be able to do the same things to you as you do to me?"

"I... hadn't imagined," Kirei managed, eyes barely opening to look at Gilgamesh. His brow was more furrowed than he'd ever seen.

"Not at all? You never wondered what it was that made a king allow you inside of him?"

"... How do y-- ahh-" Gilgamesh purposely sped his pace back up to cut him off. "Nn, how do you... control yourself so well..?"

Gilgamesh huffed a laugh.

"You're but a virgin. Did you think you would be able to remain stoic? It's unbearably good, isn't it?"

This time, Kirei laughed.

"Sinful, one might say," he said.

"Many would say. The mongrels who actually believe what you spout at them, for example. But no philosophy can convince me that pleasure this powerful is wrong."

Kirei didn't quite have the energy to laugh again, but his smile was adorable. It lingered on his face this time when he tilted his head back. It only faded with a gasp and a long groan when Gilgamesh decided to start stroking him. His noises before were already cute, but now he sounded as if he'd never had sex before.

Kirei's legs gripped him tighter and a hand, desperate for something to grab onto, buried itself in Gilgamesh's hair. The pulling was slightly painful, but not nearly enough to wipe the smug grin off Gilgamesh's face.

His orgasm was sudden- took Gilgamesh by surprise and he was almost disappointed that the fun was already over. Kirei's entire body tightened around him. His legs threatened to leave bruises and Gilgamesh's back was almost certainly bleeding by now, not to mention his head getting pulled back painfully by his hair. The pain still wasn't enough to dissuade his own orgasm and his smile returned as he emptied himself into Kirei.

Kirei's limbs fell to the bed and Gilgamesh moved his hands down to Kirei's hips, holding him in place so they would stay connected while they caught their breath.

"What was that you were saying about a second round?" Gilgamesh reminded, knowing full well that was impossible at the moment.

"I wasn't. I was trying to ask if we were going to do this again on a different occasion."

"Oh, of course we are," he answered without a second thought. Kirei sighed and closed his eyes, and Gilgamesh lamented the slow loss of blush as Kirei calmed down. They were still and silent for a good while.

"Will you be pulling out..?" Kirei asked, apparently getting impatient. Gilgamesh smiled at him.

"When it pleases me."


End file.
